The study of the effects of environmental factors on receptor sensitivity. The factors will include the effects of detergent, salt concentrations, pH and purity. The sensitivity will be studied with respect to thermal effects, oxidizing and reducing agents, metal ions and metal complexing agents. Various physical biochemical procedures will be explored with the objective of establishing configurational changes which may accompany the binding of acetylcholine receptor to acetylcholine and selected drugs. Electrophoretic studies will be performed to explore the hypothesis that agonists and antagonists bind to different sites on the receptor molecule.